Proceedings of the
World Congress on Micro and Nano Manufacturing (WCMNM 2022 )
19–22 September 2022, Lueven, Belgium
doi:10.3850/978-981-18-5180-3_RP08-0028
Effect of Femtosecond Laser Textured Copper Surfaces on Wettability and Boiling Heat Transfer Enhancement
1KU Leuven, Department of Mechanical Engineering, Division of Manufacturing Processes and System (MaPS) and Flanders Make@KU Leuven-MaPS, Celestijnenlaan 300, 3001 Leuven, Belgium
2KU Leuven, Department of Mechanical Engineering, Division of Applied Mechanics and Energy Conversion (TME), Celestijnenlaan 300, 3001 Leuven, Belgium
ABSTRACT
The increasing demand for high power density devices requires efficient heat transfer methods such as nucleate pool boiling with dielectric fluids. Tailoring of surface characteristics using laser surface texturing (LST) has been demonstrated to be an efficient way to improve boiling performance. This manuscript investigates the effect of surface textures on copper plates fabricated by femtosecond (fs) LST on nucleate boiling performance. Firstly, different microtextures (grooves and pillars) with varying spacing and depth were fabricated using fs-LST. An experimental setup was designed and developed to conduct boiling experiments with a highly volatile dielectric fluid, Novec-7000. The contact angle measurements with water indicate that the fs-LST produces superhydrophobic copper surfaces with a maximum contact angle (CA) of 162.9ï‚°, with micropillar textures having higher CA than the microgrooves. Nucleate boiling experiments confirm that deeper textures show better heat transfer enhancement in terms of higher heat transfer coefficient (HTC) and earlier onset of nucleate boiling but with a reduction in the critical heat flux.
Keywords: Femtosecond Laser Surface Texturing, Boiling Heat Transfer, Dielectric Fluids, Surface Wettability.
1KU Leuven, Department of Mechanical Engineering, Division of Manufacturing Processes and System (MaPS) and Flanders Make@KU Leuven-MaPS, Celestijnenlaan 300, 3001 Leuven, Belgium
2KU Leuven, Department of Mechanical Engineering, Division of Applied Mechanics and Energy Conversion (TME), Celestijnenlaan 300, 3001 Leuven, Belgium
ABSTRACT
The increasing demand for high power density devices requires efficient heat transfer methods such as nucleate pool boiling with dielectric fluids. Tailoring of surface characteristics using laser surface texturing (LST) has been demonstrated to be an efficient way to improve boiling performance. This manuscript investigates the effect of surface textures on copper plates fabricated by femtosecond (fs) LST on nucleate boiling performance. Firstly, different microtextures (grooves and pillars) with varying spacing and depth were fabricated using fs-LST. An experimental setup was designed and developed to conduct boiling experiments with a highly volatile dielectric fluid, Novec-7000. The contact angle measurements with water indicate that the fs-LST produces superhydrophobic copper surfaces with a maximum contact angle (CA) of 162.9ï‚°, with micropillar textures having higher CA than the microgrooves. Nucleate boiling experiments confirm that deeper textures show better heat transfer enhancement in terms of higher heat transfer coefficient (HTC) and earlier onset of nucleate boiling but with a reduction in the critical heat flux.
Keywords: Femtosecond Laser Surface Texturing, Boiling Heat Transfer, Dielectric Fluids, Surface Wettability.
